Abstract: A method for assigning a single frequency sub-channel to a plurality of MSs (Mobile Stations) in an OFDM (Orthogonal Frequency Division Multiplexing) system utilizing SDM (Spatial Division Multiplexing) with multiple transmit/receive antennas. In the method, a BS (Base Station) can effectively assign a pilot channel to estimate a downlink channel. The BS divides the single frequency sub-channel into a plurality of spatial channels, and sequentially assigns the plurality of spatial channels to the MSs having the maximum communication capacity, thereby transmitting signals of the MSs through the single frequency sub-channel.

Abstract: The present invention relates to performance improvement in a cell edge, particularly, to a method for selecting a precoder for a terminal in a multiple antenna system, wherein the method comprises: performing channel estimation for reference signals of a serving base station and another base station; determining a minimum singular value by using the channel estimation result; and if a complete collaborative feedback structure is used, feeding back a table of the determined, minimum singular value to the base stations.

Abstract: An apparatus and method for performing distributed spatial multiplexing and distributed spatial diversity in a multi-hop relay system are provided. In the multi-hop relay system, a transmitter includes an outer coder for performing outer coding on transmission data, an outer interleaver for interleaving data received from the outer coder, an inner coder for dividing data received from the outer interleaver into a plurality of frames and performing inner coding on the divided frames, and a transmitting unit for transmitting hierarchically coded frames received from the inner coder to respective Relay Stations (RSs).

Abstract: Uplink power control in a broadband wireless access system is provided. A Base Station (BS) includes a controller, a first generator, a second generator, and a modulator/demodulator (modem). The controller determines to apply one of a first power control which is slot-periodic and a second power control which is frame-periodic. The first generator generates a first power control command at a slot period using a channel quality premising a rake receiver according to the first power control. The second generator generates a second power control command at a frame period using a channel quality premising an equalizer according to the second power control, and generates a third power control command according to a predefined pattern at a slot not being able to use the channel quality. The modem transmits at least one of the first, second, and third power control commands.

Abstract: A receiving apparatus and method of a Maximum Likelihood (ML) scheme in a Single-Carrier (SC) system are provided. The apparatus includes at least two antennas, at least two Orthogonal Frequency Division Multiplexing (OFDM) demodulators, at least two subcarrier mappers, at least two OFDM modulators, and a detector. The antennas receive signals. The OFDM demodulators convert the signals into frequency domain signals. The subcarrier mappers confirm signals mapped to frequency domain subcarriers. The OFDM modulators convert the signals into time domain signals. The detector constructs at least one set for candidate transmission symbols and detects receive signals through ML detection using the set.

Abstract: An apparatus is provided for reducing a peak-to-average power ratio (PAPR) in a wireless communication system having multiple transmit antennas. A symbol generator generates symbols to be transmitted via the multiple transmit antennas, and a PAPR calculator calculates a PAPR value for each symbol. A detector detects a maximum PAPR value among the PAPR values of the symbols. A controller outputs a control signal to reduce a PAPR value of a corresponding symbol when the detected maximum PAPR value exceeds a reference PAPR value. A PAPR reducer reduces the PAPR value of the corresponding symbol upon receipt of the control signal.

Abstract: A method and apparatus for parallel structured Latin square interleaving in a communication system are provided. The method includes dividing input information bits into sub-blocks according to a parallel processing order, generating a first Latin square matrix or a second Latin square matrix by comparing the parallel processing order with a predetermined threshold, and interleaving by reading out the information bits divided into the sub-blocks according to the generated Latin square matrix.

Abstract: A method and apparatus for allocating resources for a mobile station in a communication system is provided. The method includes determining if a mobile station within a cell is located in one of a first region corresponding to a cell center, a third region corresponding to a cell edge, and a second region corresponding to an area between the first and third regions, allocating frequency resources within an entire frequency band to the mobile station when the mobile station is located in the first region, wherein the entire frequency band comprises at least a first frequency band and a second frequency band, allocating frequency resources within the first frequency band to the mobile station when the mobile station is located in the third region, and allocating frequency resources within the second frequency band to the mobile station when the mobile station is located in the second region.

Abstract: An apparatus and method for data transmission in an Orthogonal Frequency Division Multiplexing (OFDM) communication system are provided.

Abstract: Uplink power control in a broadband wireless access system is provided. A Base Station (BS) includes a controller, a first generator, a second generator, and a modulator/demodulator (modem). The controller determines to apply one of a first power control which is slot-periodic and a second power control which is frame-periodic. The first generator generates a first power control command at a slot period using a channel quality premising a rake receiver according to the first power control. The second generator generates a second power control command at a frame period using a channel quality premising an equalizer according to the second power control, and generates a third power control command according to a predefined pattern at a slot not being able to use the channel quality. The modem transmits at least one of the first, second, and third power control commands.

Abstract: The present invention relates to performance improvement in a cell edge, particularly, to a method for selecting a precoder for a terminal in a multiple antenna system, wherein the method comprises: performing channel estimation for reference signals of a serving base station and another base station; determining a minimum singular value by using the channel estimation result; and if a complete collaborative feedback structure is used, feeding back a table of the determined, minimum singular value to the base stations.

Abstract: A method and apparatus for transmitting and receiving a signal in a wireless communication system. The wireless communication system includes a transmitter with at least four transmit antennas and a receiver with at least one receive antenna. Space Frequency Block Coding (SFBC) processes are performed for input signals on a basis of two antenna pairs. Signal blocks whose number corresponds to the number of transmit antennas are output. A Space Time Block Coding (STBC) process is performed for the signal blocks generated according to the antenna pairs. Signals carried by single carriers are transmitted through the at least four transmit antennas mapped to the signal blocks.

Abstract: An optimum perturbation apparatus and method in a multi-antenna, multi-user communication system are provided. In the optimum perturbation method, upon receipt of modulation symbols, channel responses are decomposed into eigenvalues and eigenvectors by Single Value Decompositin (SVD) and a distortion value of the modulation symbols is estimated using the eigenvectors and the eigenvalues to minimize noise and interference power. The modulation symbols are precoded by combining the modulation symbols with the estimated distortion value.

Abstract: Provided are an apparatus and method for allocating resources in a mobile communication system. The apparatus includes a modulating/coding unit for modulating transmission data of one or more users according to a predetermined modulation scheme and for outputting a complex signal; a 2-Dimensional (2D)/1-Dimensional (1D) converter for converting the complex signal into a 1D signal; and a re-modulator for reconstructing the 1D signal to a 2D signal and for allocating two components of the 2D signal to two different frequency bands.

Abstract: A method and apparatus for transmitting data in a communication system. In the apparatus, a repeater repeatedly processes an input signal a predetermined number of times. A Space-Frequency Block-Coded (SFBC) encoder performs SFBC coding on the repeatedly processed input signals, and outputs at least two signal blocks in parallel. A cyclic prefix (CP) inserter inserts a CP in the signal blocks and transmits the CP-inserted signal blocks via associated transmission antennas using a single carrier.

Abstract: Disclosed a transmission apparatus in a CDMA mobile communication system. Transmission frames each have a plurality of time slots, and each of the time slots includes two data parts having the same length, a midamble intervening between the data parts, and a guard period for dividing the consecutive time slots. The transmission apparatus modulates the frames into a radio signal with a modulation signal and transmits the modulated radio signal using a plurality of antennas. A power amplifier amplifies the radio signal. A controller generates a switching control signal in a guard period of time slots of a frame associated with the radio signal amplified by the power amplifier. A switch switches the amplified radio signal from the power amplifier between a first and a second antenna in response to the switching control signal.

Abstract: An apparatus and method for determining a beamforming vector in a codebook-based transmission beamforming system are provided. In a feedback method for a receiver in a codebook-based transmission beamforming system, forthcoming channel values for a forthcoming period are generated using M present and previous channel estimates. Effective channel gains for all transmission beamforming vectors included in a codebook are calculated using the forthcoming channel values. A codebook index corresponding to the maximum effective channel gains is fed back to a transmitter.

Abstract: A receiver for ICI cancellation in a MIMO system is provided, in which a detection orderer determines a subcarrier detection order according to SINRs of subcarriers in an I-CMOS, a detector receives a vector on the subcarriers and a priori information from a decoder according to the subcarrier detection order and iteratively estimates the received vector using the a priori information, and the decoder decodes an ICI-cancelled signal according to the estimate.

Abstract: An optimum perturbation apparatus and method in a multi-antenna, multi-user communication system are provided. In the optimum perturbation method, upon receipt of modulation symbols, channel responses are decomposed into eigenvalues and eigenvectors by Single Value Decompositin (SVD) and a distortion value of the modulation symbols is estimated using the eigenvectors and the eigenvalues to minimize noise and interference power. The modulation symbols are precoded by combining the modulation symbols with the estimated distortion value.

Abstract: An apparatus and method for determining a pilot pattern in a Broadband Wireless Access (BWA) communication system are provided. In the pilot pattern determining method, an Orthogonal Frequency Division Multiplexing (OFDM) demodulator generates frequency-domain data by fast-Fourier-transform (FFT)-processing a received signal. A pilot pattern decider calculates a coherence bandwidth and a coherence time using subcarrier values received from the OFDM demodulator, and selects one of a plurality of pilot patterns according to the ratio of the coherence bandwidth to the coherence time.